Protective apparatus for railway telephone sets.



PATENTED 001 so, 1906.

No 884,764. 0. B. SGRIBNER.

PROTECTIVE APPARATUS'FOR RAILWAY TELEPHONE SETS APPLICATION FILED OUT-21. W04.

2 SHEETS-$113111 1.

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- Czarfzcsli jcrver 1;}, ,7 4, PATENTED OCT. 30,1906. SORIBNER. v

PROTEETIVE PARATUS EOE RAILWAY TELEPHONE SETS 1 1 L1'9u1on 1 ILED 001-21. 1904.

' 2 SHEETS-$113111 2.

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CHARLES E. SORIBNER, OF JERIOHO, VERh lONT, ASSIGNOR TO WESTERN ELECTRIC COMPANY, OF CHICAGO, ILLINOlS, .A CORPORATION OF lLLlNOIS.

Pnorsorive aesannrus eon RAELWAY tit-stat sman sure.

Specification of Letters Patent.

Patented Oct. 30, 1906.

Application filed October 21, 1904. Serial. No. 229,470.

T all whom, it may concern:

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Be it"knomi that I, OHARLEs E. SCRIBNER, a citizen of the United States, residing at Jericho, in. the county of Ohittenden and State of Vermont, have invented a certain new and useful Improvement in Protective Apparatus for Railway Telephone Sets. of which the following is a full, clear, concise, and exact description.

My invention relates to electrical apparatus, such as telephone sets, and has for its object to provide improved means for controlling the operative condition thereof and for protecting-"the user of such apparatus from abnormal currents with which the line conductors leading .thereto may be accident-ally charged.

It is customary at'the present time to provide telephone-lines in association with electric railways, and telephone sets are located at 1ntervals,to be used in communicating with the despatcher who controls the movements of the cars and in reporting trouble or accident on the line. Telephone-lines of this character, being associated with the powertransmission circuits of the road, are par-- ticularly subject to high-potential crosses, and when such across exists the use of the tele hone sets connected with the line is atten ed by; considerable danger to the user. It, is, therefore necessary in the case of such lines to malre especial provision for the protection from abnormal currents of the parts ef the associated telephone sets with which the user is liable to come into contact, audit is mainly toward meeting this requirement that my invention is directed.

One feature of my invention consists in meansactuated in obtaining access to the containing-case of the apparatus for renderng operative a protective or safety device which before the user has had an opportunity to touch any of the parts Within the case will act to prevent any abnormal current that may exist on the line from being communicated to the apparatus. '1 preferably employ fusesin connection with the safety appliance referred to which are included in the circuit of the apparatus, said circuit being arranged to be closed as the door of the containing-case is opened, so that the fuses will blow while the door is being opened, and thus constituting a signal where by the person desiring to use the instrument is apprised of the abnormal and dangerous condition of the line. I also preferably provide in association with the fuses a safety appliance of a different character, such as a lightningarrester, to cooperate with the firstunentioned protective device in the protection of the apparatus and safeguarding of the user.

Another feature of my invention lies in mounting the protective apparatus and the telephone apparatus of' the set in searate groups with a grounded metallic shie d be tween them, so that any dangerous highpotential condition that may exist in the compartment wherein the protective devices are mounted may not be communicated to the telephone apparatus, but may instead be diverted through the grounded shield interposed between the two groups.

Another feature consists in improved means actuated in closing the containingcase of the instrument for automatically disconnecting'the set from the line and opening its local circuit to guard the apparatus from dangers from external sources, such as abnormal currents, and also to avoid waste of current when the device is not in use.

I will describe my invention more particularly by reference to the accompanying drawings, which illustrate a telephone set equipped in accordance with my invention, and theparticu'lar parts, improvements, or combinations which I regard as novel will be pointed out in the appended claims.

Figure l is a front view of the containingcase of a telephone set embodying my in* vention with the door of the case ooened. Fig. 2 is 'a vertical sectional view on line 2 2 of- Fig. 1. Fig. 3 is .a transverse sectional view of the containing-case on line 3 3 of Fig. 1, and Fig. e is a diagrammatic view of the circuits of the telephone set to illustrate the application of my invention thereto.

The same letters of reference are usedto designate the same parts in each of the if abnormal currents are present in the line paratus, the case having a door a adapted to 25 their respective ELDVllS to complete it cirthe same. The anvils Z) coi seidcontrollingtrmsznitt 5 in clips 9 g and g g respectively, secured to e0.

opening and closing to the connection to saith th cgs'i grs '5 end disconnection of the apparatus of ti e ""et' :lnses Whe I with the circuit with which it may he associeted.

Two pairs of sw perstus are wrong d to movement of he dost a t. t provided with J 1s ;--l

10 may he carried by an n orig-ht plate 5, L o

ed upon the n rnovehlo shelf Ff. The stud cells 10 springs may he provided with e "plunger (i, moved h supported by the bracket 6 and adapted to tion out of be moved by the door of the case it is Which are then s to one closed to permit said springs b c to sepe ate transmits; When plunger may carry a cam d, which, when the door is closed,!lies out of engagement with said springs which rest out of contact With b pre their envils, to maintain the apparatus dissurface ol" ssid (low connected from the line. A helical sp no is of s: Kl u may serve to move the plunger upon the i losed ti opening of the door to cause the cam d to enoi f 7 ed gage said springs and close the some upon i from their envils b c, respectivelv. The opened, a sprin 32 serves to wove th 1. b cuit connections of the apparatus with the telephone line. 1 preferably provide a 6 upon the aretus again. L nee. inner surface of the door adapted to engage the line and also to prevent useless consum the plunger of as the 1001 is closed to operate tion current in the local circuit of switches maybe connectedwith the apnea-2c will he noted that the protective detus of the set, While the springs I) c are con- "vices, incliuling the lusesf'f" and the carbon nected with lfusesff electrically united wi h erresteis m m end the switch controt the line-wires The fuses may be mounted ling their connection'v v the line, ere mounttogether on the snelf N, so that the upright Loo e suitable insulating olOck it. The tennine-i etellic plate or pertitionb" is interposed heclips g g are electrically connected with tween them and the generator and the switch switch-fingers 7c 7c, respectively, carried by 0 0 that controls the local circuit 0* the insulating-block 72 The fingers is Is while the metallic body of the shel; 40 adapted when the shelf in its normal point rposed between them. and the sition Within the containing-case to "ti ment. in: the shell and it switch-springs Z- Z, which are mounted connected to the earth t but insulated Tom the Well of the conts shield to prevent any da case and Which. form the terminals of ins fleriist inthc piotettme-dqwicc linewviresleading to the ins ti'uinent.

As the door of the spring (Z moves the plnng to Chi springs b 0 against their snvils c c", th connecting the telephone set the l the ifuses interposed beta" 1nd and the line-wires. in si /noun rents are present in the line the I blown before the persondesiiing to use the telephone has an opportunity to grasp the telenhone instrument T, thereby protecting him i'i'oin injury and sppiising him of the con- .t'lhl 0 close the circuit and eted upon lix dition of the apparatus. openin the circuit and il'iSSl: l

A second safety appliance is preferably ine1 out '1 terposed between the fuses and the eppem-- I hinstion with el-i v tus oi the set Which may comprise a. pair of l hung-case there-tor,

.lightning-ztresters m m, Whose line-plates s switches controllii' are connected with opposite sides of the circircuit, end means cnit and the i'eineining eted )LQCl to L1 with the gi'ounded 1"" tree on 5 chi-e05? Blcniient w I the a i as the case is opened, and the personattempting to use the a paratus protected,

3. The combination with electrical a pa.

- rates, of a containing-case therefor, a o er 5' for said case, a circuit for the apparatus,

the circuit the fuses will be-blown asthe door is opened, and the person attempting to use aratusprotected. 4

. 4. he combination with a. telephone set,

being adapted to be opened by the door when 1 it is closed, and means actuated in opening said door, adapted to close said switches; whereby if abnormal currents are present in the line, due to a cross with said high-tension circuit, the fuses will be blown as the dopr is opened, thereby protecting theperson attempting to use the set. 5. The combination-with a telephone set of a containing-case therefor, a door for sai case, a telephone-line with which said set is connection of said set with the line, fuses in the circuit controlled by saidswitch-springs,

-plungcrs controlling said switch-springs, said door being adapted upon the closure thereof to-move'said .plungers to o switch-springs, and springs actuate opening of said door, to'move said plungers to close said springs; whereby ifabnornial currents are present in the line, the fuses will be blown as the door is opened, thereby protepting the person attempting to use the teleone.

p 6. The combination with a telephone set, of a containing-case therefor, a door for said case, a circuit for said set, switches control ling said circuit, fusesin said circuit, a lightning-arrester connected from the circuit between the fuses and the telephone apparatus to ound, and means actuated in opening said door for closing said switches; W ereby abnormal currents in the circuit will be diverted to earth through the arrester as said whereby if a normal currents are present in of a containing-case therefor, a door for said 1 associated, switch-springs controlling theti t e door is opened in case the fuses are not blcwn or an arc is formed therein.

7. The combination with electrical mesh amsm, of a containing-case therefor, a door for said case, switch-springs controlling the circuits of said mechanism, plungers mounted within the case for said switcl 1springs, the door of the case being adapted when the same is closed to engage and move said plungers to separate said switch-s rings, and

elprings for said plungers adapts when saidoor is opened to move the plungers to close said switch-springs.

8. The combination with a telephone set, of a containing-case therefor, a door for said case, switch-springs controlling the circuits of said telephone set, one set of said springs being included in the local transmitter-circuit, the remaining sets of switch-springs beingincluded in the portion of the circuit connected with the line, plungers fer operating said switch-springs, the inner face of thedoor of the case adapted when the same is closed to move said plungers to separate said switchsprings, and springs adapted when the door s opened to move said plungers to ciose the switch-springs,

. 9., In a telephone set the combination with the telephone apparatus of a protective pplianc therefor, and a metallic mounting aving a part thereof interposed as a shield be tween said telephone apparatus and protectivea pliance, said part being grounded,

where y dangerous currents may be diverted vfrom said telephone apparatus. 7 I 10 The combination with electrical mechanism, of a-containing-case therefor, a door for said case, switch-springs controlling the circuits of said mechanism, plungers mounted within the case, cams carried by said plungers adapted tooperate said springs, the door of said case being adapted when closed to engage said plungers and cause said cams to separate said springs, and springs for said 

